Question

4. A test for drug use involves addition of 10.00 mL of colorless reagent to 10.00 mL urine. If drug residue is present in the sample the solution turns blue ( 605 nm, <= 18,200 M-'cm'). Because other things in urine may give slightly positive results only tests that measure a minimum concentration of 5.0x10° drug residue in the original urine sample are considered positive for illegal drugs. When you measure the sample using the test described above and get an Abs of 0.539 at 605 nm (b = 1 cm). Do you conclude that this person has been using illegal drugs? Explain. ITUUUUUUU 5. A Student decides they want to analyze the green Fruit Loops that we threw away. They obtain the spectrum pictured below. Using what you learned about the food dyes in this experiment. propose how you think the green color was created in these loops. Wave 103

Answer 1

(4) From Lambert Beer's 'an we get A = Excale where, A- Absorbance E: Molas absorbtivity C: Molas concentration be path length of photo cell here, as 0. 539. &= 18,200 cm bil con, Ca? 0.539 - 18200 Ml & ex sur = 0.539 to 10.0 verine botroval =2 182oom o.539 78200 Von = 2:96X10*5m 10.00 of color ter reagent was added u dilution factor of mine. 10410/ rom Concentration of drug in unine = 2.96x10m & dilation factor = 2.96 4105 es x2 - S.92 xlors M. here, 5.92 x105m minimum concentration 50xlors M So, here person has been using illegal drug.